This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Objective: To compare nicotine pharmacokinetics and subjective effects of three newer smokeless tobacco potential reduced exposure products (PREPs;Ariva, Revel, Stonewall) to moist snuff (Copenhagen) and medicinal nicotine (Commit lozenge). Methods: Ten subjects completed a randomized, within-subject, cross-over study. Subjects used one product for 30 minutes at each of five laboratory sessions. Maximal nicotine concentration (Cmax) was determined and area under the concentration time curve (AUC) was calculated for a 90 minute period (during use and 60 minutes post-use). Nicotine craving, withdrawal symptoms and ratings of product effects and liking were measured during product use.